This invention relates to a pen recording apparatus suitable for use in recording characters, symbols, graphs, etc., on a recording sheet with a pen by moving the pen and recording sheet relative to each other in two axial directions which intersect each other.
The applicant has previously developed a pen recording apparatus provided with a plurality of pens of different colors which enables characters, symbols, graphs, etc., to be recorded in lines of a plurality of colors as the operator uses pens of arbitrarily selected colors.
This type of pen recording apparatus can be put to various forms of use. However, the most popular mode of use is considered to be where characters and symbols are recorded in one color while graphs are recorded in a multitude of colors. When the pen recorder is utilized in the manner referred to hereinabove, what often happens is that, after the characters and symbols are recorded in a certain color and the graphs are recorded in a multiplicity of colors, the recording of characters and symbols is performed once again. When this is the case, if the color used in the final operation of recording graphs is the same color that is used in recording characters and symbols, then it is possible to record characters and symbols immediately after the recording of graphs is finished. However, in the event that the color of the pen used in the final operation of recording graphs is not the same color that is used in recording characters and symbols, it is necessary to replace, after the operation of recording graphs is finished, the pen used for recording graphs by a pen that was previously used for recording characters and symbols. Thus, in the prior art, it has hitherto been necessary for the operator to actuate an operating member, such as a color change key or a color change switch, following the completion of the operation of recording graphs. This operation is troublesome. If the recording of characters and symbols was performed without actuating the operating member, then the characters and symbols would be recorded in colors which are not the color in which they were intended to be recorded. This would make it necessary to erase those characters and symbols recorded in an undesired color. If no eraser means were provided, it would be necessary to replace the old recording sheet by a new one and start another recording operation.